I threw mine into a 5 gal bucket....but I had only a few.....
rack?....you could throw them into a different level as you clean....or use a trash can ....they can jump a bucket....
some people clean tubs as they go....other people have double the amount of tubs...they just pull old tub...slide in new one and put rats into new tub right away....stack dirty tubs....and clean later...as in 20 minutes or days later....I cleaned like 12 at a time.....I know people that wait days...but they dry and are harder to clean.....(no I didn't wash mine all the time...just dump and load)(I did wash outside and used sunshine to dry them from time to time...
clean the bucket you mean?....for the water lines ?....dish soap for your dishes....why not?....vinegar?....mouth wash....could use bleach...but it takes too long to rinse and get rid of the smell.....you could have a couple buckets also....
...
-----
........JY